This invention relates to an apparatus for utilizing a utilizing a forty-two volt (42 V) power distribution system (42 V alternator, 36 V battery) to control multiple vehicle systems with a single controller including independent diagnostics for each system.
As more electrically controlled devices are incorporated into vehicles, the power supply for running these devices must also be increased. The standard twelve volt (12V) battery with a fourteen volt (14V) alternator that has traditionally been installed within the vehicle does not provide sufficient power to meet the increased demands.
To meet the demand for an increased power supply, the automotive industry is moving towards a thirty-six volt (36V)/forty-two volt (42V) alternator system. As this transition is made, hybrid systems that can support both voltages are needed. These hybrid systems are referred to as a twelve volt (12V)/thirty-six volt (36V) battery power distribution system or a fourteen volt (14V)/forty-two volt (42V) power distribution system. The use of a 36V/42V system permits the use of electrical components that could not previously be used in 12V systems. The 36V/42V system provides direct current (DC) to power motors that run the various vehicle operating systems such as window regulators, sunroofs, power locks, power mirrors, power seats, etc.
In a 36V/42V system, alternating current (AC) electric induction motors can be used for running the various vehicle operating systems. AC induction motors have a primary winding or stator that is connected to the power source. Current flow through the primary winding induces current flow in a secondary winding or rotor that rotates with respect to the stator. The use of AC induction motors requires conversion of the direct current power supply to alternating current. Thus, it is desirable to provide a system that can convert direct current to alternating current, and which can simultaneously provide power to multiple motors with unified control to operate multiple vehicle systems.
Typically, single-phase AC motors require an auxiliary winding with capacitors to start rotation of the rotor, which is expensive. Further, once the motor is running it can be difficult to accurately control the acceleration and deceleration of the motor to efficiently operate the respective vehicle system. Thus, it is desirable to provide a simplified and improved starting mechanism for the induction motor. The motor should also have improved feedback control for efficient operation.
In a disclosed embodiment of this invention, an apparatus for controlling multiple vehicle systems includes a 36V/42V power distribution system that generates direct current. A converter mechanism is electrically connected to the power distribution system to convert the direct current to alternating current. A plurality of induction motors are used to operate various vehicle systems. The motors receive alternating current via electrical connections between the converter mechanism and the motors. A plurality of control members actuate the various vehicle systems and a central processor is connected to each of the motors for providing control signals to the motors based on input from the control members.
In one embodiment, at least one sensor is associated with each of the motors to monitor voltage of the respective motor and generate a specific diagnostic signal for that motor that is sent to the processor. The processor generates a warning signal when any of the diagnostic signals indicates that voltage within the respective motor is less than a predetermined limit.
In one embodiment, the induction motor for operating a vehicle system has a stator electrically connected to the converter mechanism and a rotor that rotates with respect to the stator. A central processor is connected to the motor to provide a control signal to a power converter that controls power into the motor based on input from a control member used to activate the respective vehicle system. A piezoelectric material is mounted on the rotor and is responsive to the centrifugal force generated as the rotor rotates with respect to the stator. The piezoelectric material generates a feedback signal for regulation of acceleration and deceleration of the rotor.
In another embodiment, the induction motor with the rotor includes a piezoelectric material that is associated with the control member such that when a mechanical force is applied to the control member a voltage pulse is generated by the piezoelectric material to start the motor.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.